This invention relates to machines for manufacturing all types of blown hollow articles made of thermoplastic materials and particularly those having a neck opening.
Blow-molding machines are known in which an extruded parison is enclosed in a mold cavity and, after serving the parison from the plastics material in the extrusion nozzle, the mold is moved relative to the nozzle to enable a blow pin to be inserted in the open end of the parison, blowing air then being admitted through the blow pin to expand the parison to the configuration of the cavity to mold a hollow article. If the molds are moved bodily from the extrusion nozzle to the blow pin, vibration problems arise, particularly if the molds are very heavy, and to reduce vibration machines have been designed in which the extruder and blow pin are moved while the molds remain at the same station. One such machine is described in U.S. Pat. No. 3,837,780 issued Sept. 24, 1974 to Paul Strong.
An object of the invention is to provide an improved machine which practically eliminates objectionable vibration.
A further object is to provide a machine which provides for trimming excess plastics materials from the blown hollow articles within the platens, for continuous extrusion, and for oriented removal of the articles.